Tubular air diffuser



June 1, 1965 w. w. KENNEDY 3,186,329

TUBULAR AIR DIFFUSER Filed May 21, 1962 3 Sheets-Sheet 1 IN VEN TOR.

ll d/er A flmedy BY h f w Udfim I ATTORNZSXS June 1, 1965 w. w. KENNEDY3,186,329

TUBULAR AIR DIFFUSER Filed May 21, 1962 3,Sheets-Sheet 2 INVENTOR. lid/ter M ATWY/Yea/y BY (J Ifu AZM- J ATTORNEYS June 1, 1965 w. w KENNEDY3,186,329

TUBULAR AIR DIFFUSER Filed May 21, 1962 3 Sheets-Sheet 5 INVENTOR.

ll d/cr /1. Kennedy BY dick flu ATTORNEYS United States Patent 3,186,329TUBULAR AIR DIFFUSER Walter W. Kennedy, Rockford, Ill., assignor toBarber- Colrnan Company, Rockford, 1th, a corporation of Illinois FiledMay 21, 1362, Ser. No. 196,366 Claims. (Cl. 98-40) This inventionrelates to a tubular type diffuser mounted in the end of an air duct foruniversal adjustment to determine the angle of discharge of the airstream delivered through the duct.

The general object is to provide a diifuser of the above characterwhich, as compared with prior constructions, is simpler and lessexpensive to manufacture and which, for a given axial length, providesfor a wide range of adjustment of the discharged air stream.

Another object is to provide for greater angular adjustment of thedischarged air stream than has been possible heretofore withoutsubstantially shortening the range of throw of the stream for a givendischarge velocity.

A further object is to utilize a novel arrangement of concentric tubesto achieve the foregoing objects.

The invention also resides in the novel sizing and mounting of the tubesof the ditfuser relative to each other and to the duct end.

Other objects and advantages of the invention will become apparent fromthe following detailed description taken in connection with theaccompanying drawings, in which:

FIGURE 1 is a fragmentary elevational view of part of an airconditioning duct equipped with a discharge outlet embodying the novelfeatures of the present invention.

FIG. 2 is a perspective view of the improved outlet.

FIGS. 3, 4 and 5 are sections taken respectively along lines 33, 44 and5-5 of FIG. 2.

FIGS. 6, 7 and 8 are schematic views through a diameter of the ductshowing diiierent adjusted positions of the outlet unit.

FIG. 9 is an end view of FIG. 8.

The improved air diffuser is especially suited for use in factories,auditoriums and like installations where artistic appearance may besacrificed to some extent in order to achieve a wide range of adjustmentof the angle at which the air stream is discharged into the room andalso convenience in changing the adjustment. Accordingly, the diffuseris shown in the drawings mounted in the outlet end of a cylindrical ductit) branching from a main supply duct 11 and adapted for universaladjustment to direct the discharge air stream 12 at any angle relativeto the duct axis within a cone 13 having an angle of thirty degrees forexample. Herein, the diffuser is secured to the duct end through themedium of a mounting ring 14 of right angular crosssection having oneflange 15 telescoped with and fastened by screws 16 to the duct end. Asecond and inturned flange 17 constitutes a mounting plate for thediffuser and defines at its inner edge 18 a circular hole concentricwith the duct axis and somewhat smaller in diameter than the duct.

In the form shown for purposes of illustration, the diffuser 9 comprisesgenerally a ring 21 journaled on the inner edge portion of the flange 17to turn about the duct axis and, through the medium of trunnions 22supporting an axially elongated tubular deflector unit 23 for swingingadjustment about a diameter of the duct and through the desired angularrange 13. In the present instance, the ring 21 is composedof two parts21 and 21 formed around their edges with shallow ribs 25 which telescopeas shown in FIG. 4 within the hole 18 of the flange and are held in faceto face relation by angularly spaced screws 26. The ribs are onlyslightly smaller in diameter than the flange edge 20 which thus providesa bearing in which the "ice ring is journaled for turning about the ductaxis. The combined height of the ribs is slightly less than thethickness of the flange 17 so that with the screws tightened properly,the ring parts grip the flange under enough pressure to trict-ionallyretain each selected position of the ring.

While the trunnions 22 may be journaled in either the ring 21 or theunit 23, the opposed faces of the ring parts are recessed at 28 in thepresent instance (see FIGS. 3 and 5) to provide diametrically alinedsockets in which the outer ends of the trunnions are journaled butgripped under sufficient pressure to provide the friction necessary forretaining the selected angular adjustments of the tubular unit 23.Herein, the headed inner ends of the trunnions are secured rigidly as bywelding 29 to the outer cylindrical tube 30 with the two trunnionsalined accurately. To allow for Wide angles of horizontal swinging ofthe unit 23 when several of the latter are disposed side by side, thetrunnions are spaced substantial distances from the ends of the tube,being about midway between the ends in this instance.

To provide for discharge of the air stream 12 into the room at an anglecorresponding closely to each angular position of the tube 30,additional and successively smaller tubular deflectors 32 and 33 arearranged Within the tube 30 concentric therewith and rigidly securedthereto as by spokes 34 which may comprise radially extending rodswelded to the tubes 39, 32 and 33 but are shown herein as relativelythin and flat and angularly spaced apart with their laterally bent ends35 spot welded to the opposed surfaces of the adjacent tubes. The latterare substantially equal in axial length and radially spacedequidistantly apart, there being, in the present instance, three tubes4% inches long spaced 1% inches apart in this instance for an airdischarge outlet nine inches in diameter as determined by the internaldiameter of the ring 21 as compared with a duct diameter of twelveinches. For such a duct size and arrangement of the trunnions relativeto the outer tube 30, the latter is preferably about 4% inches indiameter thus leaving an open annular space 37 between the tube and theinner periphery 38 of the ring 21 and of uniform radial width when theunit 23 is alined axially with the duct 10 as shown in FIG. 6.

The lengths and number of the concentric tubes 30, 32 and 33 employed inthe unit 23 will be determined by the size of the duct 10 in relation tothe desired cone 13 of adjustment of the air streams. In each instance,it is desirable to correlate the lengths and radial spacing of theconcentric tubes so that at the maximum angle of adjustment of the unit23 about a diameter of the duct, the tubes will, as shown in FIG. 7,coact to substantially block and prevent a clear line of sight throughthe unit axially of the duct. Because of this, the surfaces of the tubesact as bafiles for deflecting the air stream flowing out of the duct andcausing the same to be discharged into the room at an angle closelyapproximating that at which the unit is set.

Such accurate correlation between the angular position of the tubularunit 23 and the path of the discharged air stream 12 is attributable toseveral factors and is achieved, I have found, in spite of thesubstantial width of the annular space 37 which is provided around theunit in order to allow a wide range, 60 degrees in this instance, of theunit. By virtue of the relatively close spacing of the tubes 30, 32 and33, turbulence in the air stream as it enters the inner ends of thetubes is dissipated and a straight forward flow is induced by the actionof the tube surfaces before the stream is discharged from the outlet endof the unit. A substantial volume of air flows out of the duct throughthe annular passage 37 around the tube 30 and generally along thelatter, but, owing to jet action at the discharge end of the tubularunit, such air is drawn into the main stream 12 around the peripherythereof and without destroying the well defined shape thereof orreducing the length of the throw. For a given velocity within the duct,a substantially longer throw is achieved than would be possible if thetubes 32, 33 were omitted.

To produce a straight axial discharge of the air stream 12, the tubularunit is disposed with its axis coincident with the duct axis as shown inFIG. 6. In this case, the annular space 37 between the tube 39 and theinner edge of the ring 21 is of uniform radial length.

As the unit is swung in either direction about the diametrical axisdefined by the trunnions 22, for example to the position shown in FIG.8, the width of the space 37 adjacent the trunnions remains unchangedbut at other points around the tube 30, the space varies in width. Inthis position, it will be apparent that the outer surfaces (1 on oneside half of each of the tubes 30, 32 and 33 are disposed at an acuteincluded angle relative to the direction of air flow through the ductand thus become effective as baffles to intercept corresponding areas ofthe air stream forced through the ring 21 and deflect such portions ofthe streams laterally causing it to be discharged into the room at anangle corresponding to the angular position of the unit. It will benoted that because of the spacing of the outer surface a of the tube 30inwardly from the ring 21, this surface also contributes to thedeflecting action.

The inner surfaces b on the other halves of the tubes are inclined atthe same acute angle and cause deflection of the remainingcross-sectional part of the air stream by an equal amount. At all pointsaround the outer tube 30, air flows out of the duct thus by-passing thetubular unit 23 as shown by the arrows in FIG. 8 but, as pointed outabove, such air is quickly aspirated into the stream 12 immediatelybeyond the tubes and does not change the angle of discharge or thelength of throw of the stream 12.

The desired long range of throw of the discharged air streams 12 andclose correspondence between the angular position of the tubular unit 23and the path of discharge of the stream 12 is maintained over the full60-degree range of adjustment of the unit. This is attributable toaction of the successively smaller inner tubes 32, 33 in substantiallyblocking the line of sight through the outer tube 30 thus preventing thedevelopment of turbulence within the latter and the consequence loss ofvelocity and control of the stream within the unit. Such blocking actionis illustrated in FIG. 7 in which the unit 23 is disposed in one limitposition with the inner and outer ends of the tube 30 in contact withthe ring 21 on diametrically opposite sides of the trunnion axis.

From the foregoing, it will be apparent that the plate 17 and one of therings, for example 21*, together form an annulus covering the end of theduct and defining by its inner edge 38 a hole which is larger than thetube so as to permit the tube to be swung about the transverse axisdefined by the trunnions 22. At the same time, the trunnions are clampedfrictionally by the screws 26 against the ring 21 whose annular shoulder25 (FIG. 4) is journaled in the inner edge 18 of the plate 17. Thus, in

this instance, the trunnions 22 and the ring 21 form a connectionbetween the annulus 17, 21 and the tube and support the latter foradjustment about the two perpendicular axes.

I claim as my invention:

1. In combination with a duct adapted for the flow of air axiallytherethrough, an annulus adapted to be secured to the end of a ductconcentric with the duct axis, an elongated tube extending through thehole defined by the annulus and having an outer peripheral surfaceradially spaced inwardly from the inner periphery of the annulus, saidtube receiving at its inner end air delivered through said duct anddischarging a stream of such air from its outer end in a directiondetermined by the angle included between the axes of said annulus andsaid tube, and means connecting said annulus and said tube andsupporting the latter for turning of the tube about the axis of saidannulus and also for swinging about a transverse axis extendingdiametrically across said hole and lying substantially in the plane ofthe annulus, said connecting and supporting means including twotrunnions projecting radially from opposite sides of the tube along saidtransverse axis and disposed intermediate the ends of said tube wherebyto provide, in the different angular positions of the tube about its ownaxis, for swinging of the tube about said transverse axis as permittedby the space between the annulus and the tube.

2. An air diffuser as defined in claim 1 in which said trunnions aredisposed about midway between opposite ends of said tube whereby toprovide a wide range of angular swinging of the tube about saidtransverse axis.

3. An air diffuser as defined in claim 1 in which the different angularpositions of said tube about said two axes is maintained by frictionbetween .opposed surfaces in said connecting means.

4. An air diffuser as defined in claim 3 in which said friction isderived from a clamping screw extending between a part of saidconnecting means and a part of said annulus.

5. An air diffuser as defined in claim 1 including a plurality of tubessuccessively smaller than and approximately the same length as saidfirst tube, and spokes rigidly connecting each adjacent pair of saidfirst and second tubes and supporting the same in concentric relationwhereby air delivered into said first tube is divided into a pluralityof concentric tubular streams each guided in its flow substantiallythroughout the length of the first tube.

References Cited by the Examiner UNITED STATES PATENTS 1,754,961 4/30Neilson 9s 2,326,858 8/43 Honerkamp 98-40 FOREIGN PATENTS 165,081 9/55Australia.

ROBERT A. OLEARY, Primary Examiner. EDWARD J. MICHAEL, Examiner,

1. IN COMBINATION WITH A DUCT ADAPTED FOR THE FLOW OF AIR AXIALLYTHERETHROUGH, AN ANNULUS ADAPTED TO BE SECURED TO THE END OF A DUCTCONCENTRIC WITH THE DUCT AXIS, AN ELONGATED TUBE EXTENDING THROUGH THEHOLD DEFINED BY THE ANNULUS AND HAVING AN OUTER PERIPHERAL SURFACERADIALLY SPACED INWARDLY FROM THE INNER PERIPHERY OF THE ANNULUS, SAIDTUBE RECEIVING AT ITS INNER END AIR DELIVERED THROUGH SAID DUCT ANDDISCHARGING A STREAM OF SUCH AIR FROM ITS OUTER END IN A DIRECTIONDETERMINED BY THE ANGLE INCLUDED BETWEEN THE AXES OF SAID ANNULUS ANDSAID TUBE, AND MANS CONNECTING SAID ANNULUS AND SAID TUBE AND SUPPORTINGTHE LATTER FOR TURNING OF THE TUBE ABOUT THE AXIS OF SAID ANNULUS ANDALSO FOR SWINGING ABOUT A TRANVERSE AXIS EXTENDING DIAMATERICALLY ACROSSSAID HOLE AND LYING SUBSTANTIALLY IN THE PLANE OF THE ANNULUS, SAIDCONNECTING AND SUPPORTING MEANS INCLUDING TWO TRUNNIONS PROJECTINGRADIALLY FROM OPPOSITE SIDES OF THE TUBE ALONG SAID TRANSVERSE AXIS ANDDISPOSED INTERMEDIATE THE ENDS OF SAID TUBE WHEREBY TO PROVIDE, IN THEDIFFERENT ANGULAR POSITIONS OF THE TUBE ABOUT ITS OWN AXIS, FOR SWINGINGOF THE TUBE ABOUT SAID TRANSVERSE AXIS AS PERMITTED BY THE SPACE BETWEENTHE ANNULUS AND THE TUBE.